Bio:Acting indirectly at first, Ultron encountered fellow Avengers enemy Eric Williams (the Grim Reaper) and supplied him with the coma-ray technology the Reaper would later use against the Avengers. Later, adopting the super-criminal guise of the Crimson Cowl to conceal his robotic nature, Ultron recruited Avengers foes Klaw, Melter, Radioactive Man and Whirlwind and formed a new Masters of Evil group to destroy the Avengers. Avengers butler Jarvis, secretly mesmerized into serving Ultron, supplied the Masters with plans of the Avengers Mansion security system and even posed as an alternate Crimson Cowl (supposedly the real one) to help conceal Ultron's true identity. In the end, the Avengers defeated the Masters with the aid of the Black Knight (Dane Whitman), who had infiltrated Ultron's Masters-and Ultron was exposed as the true Cowl, though he escaped.